The best shows have not been officially released so I would pursue the usual torrent sites. Many shows are available in soundboards or excellent audience recordings (since the shows were in smaller clubs). I think you would really enjoy 12-21-79 as a follow-up to the Kean show. I'll be happy to send you anything you want so just let me know.
That is a good show Billyd,the After Midnight smokes and the Positively 4th Street in spite of the numerous vocal gaffes has some sparkling jams in it.I have been downloading and listening to all the shows from Oct 79' through March 80',to refresh my memory on that particular JGB lineup,I am going to work my way through Aug.80'.